Beam switching tube counting circuit with particular transfer means between electrode groups



A. SOMLYODY 3,157,816

TH PARTICULAR Nov. 17, 1964 BEAM SWITCHING TUBE COUNTING CIRCUIT W TRANSFER MEANS BETWEEN ELECTRODE GROUPS Filed Dec. 31. 1962 A wwwJDm BY W &. fl

ATTORNEY United States Patent 3,157,816 BEAM SWITCHTNG TUBE COUNTING CIRCUIT WITH PARTICULAR TRANSFER MEANS BE- TWEEN ELECTRODE GROUPS Ar'pad Somlyody, Raritan, N.J., assiguor to Burroughs Corporation, Detroit, Mich, a corporation of Michigan Filed Dec. 31, 1962, Ser. No. 248,402 5 Claims. (U. 315--8.5)

This invention relates to electronic counting circuits and particularly to counting circuits using multi-position magnetron beam switching tubes as the counting elements thereof.

Magnetron beam switching tubes are counting devices which include an electron-emitting cathode and ten groups of electrodes, each of which is adapted to receive an electron beam from the cathode and to provide an output signal therefrom. Each group of electrodes includes a target electrode which receives an electron beam and produces an output signal therefrom, an auxiliary collector electrode, a spade electrode which forms and holds an electron beam on its associated target electrode, and a switching electrode which may be used to switch an electron beam from one group of electrodes to the next to perform the counting operation.

In the operation of beam switching tubes as counters, counting pulses are applied to a tube in either a singleended or double-ended drive arrangement. In a doubleended drive circuit, the switching electrodes of a tube are connected in two sets, with alternate electrodes in each set, and each set is connected to one of the outputs of a flip-flop. As the flip-flop changes state, an electron beam is switched by one position in the tube. In a single-ended drive arrangement, a single source of pulses is connected to all of the switching electrodes connected together in common. Such a single-ended drive arrangement is generally preferred, among other things, for its economy and simplicity. However, in the past, in single-ended drive circuits, it was necessary to provide driving pulses which had a measured time duration to insure that each pulse would cause an electron beam to switch by only one position at a time. Such time-measured pulses are known as quantized pulses.

Thus, the objects of the present invention are concerned with the provision of an improved counter circuit using a magnetron beam switching tube as the counting element thereof, the circuit including a single-ended drive arrangement which does not require quantized driving pulses.

Briefly, a counter circuit embodying the invention uses a rnulti-position magnetron beam switching tube as the counting element thereof. In the tube, each target electrode is coupled to the adjacent leading spade electrode through a selected coupling circuit which operates with the various applied potentials so that, with an electron beam flowing to a tube position, a counting pulse applied to all of the spade electrodes can affect only the spade electrode next to the tube position to which the electron beam is flowing. Thus, the beam is caused to switch by one position to the next leading position. Each counting pulse applied thus causes an electron beam to switch by one position. The coupling circuit is such that Lecounting pulses need not be quantized pulses.

The single feature of the drawing is a schematic representation of a circuit embodying the invention.

The circuit shown in the drawing is particularly suited for use with magnetron beam switching tubes such as the type 6700 tube and with similar devices sold by the Burroughs Corporation and known as BEAM-X switches. These devices are cylindrical in form, but they are shown schematically in linear form as tube It) in FIG. 1. The tube 16 has an envelope 12 which contains a central "Ice cathode 14 and ten groups of electrodes spaced radially equidistantly from and surrounding the cathode. For simplicity, only four groups of electrodes are shown numbered 1, 2, 3, and 4. Each group of electrodes includes a spade electrode 16 and a target electrode 18, with each spade electrode serving to form and hold an electron beam on its corresponding target electrode which itself provides an output signal from the beam. A switching electrode, known as a switching grid and normally used for switching an electron beam from position to position, is also included in each group of electrodes. In the BEAM-X switch, an auxiliary electrode is provided between each target and the adjacent leading spade, and the auxiliary electrode acts as a current collecting electrode in some circuits. Since the switching grids and auxiliary electrodes are not required in the present invention, they are not shown.

The tube 10 also includes suitable means (not shown) for providing an axial magnetic field which operates with electric fields within the tube to form an electron beam and switch it from one group of electrodes to the next. Such means may be an external permanent magnet or internal magnets or the like. The electrodes themselves may be permanent magnets. The direction in which an electron beam is urged, that is clockwise or counterclockwise, is called the leading direction, and is always the same and is determined by the orientation of the electric and magnetic fields.

In the circuit of the drawing, the cathode 14 is coupled to a source of reference potential such as ground and the spade electrodes are coupled through spade load resistors 26 to a bus 28 which is connected to a positive DC power source Vs of about 55 volts.

The target electrodes 18 are connected through suitable load resistors 50 to a bus 54 which is coupled to a positive DC. power source Vt of about volts. In addition, an auxiliary output tap 58 is provided at each target for connection to a suitable utilization device or circuit. Each target is also coupled through a series-connected resistor 66 and diode 62, oriented as shown, to the adjacent leading spade electrode. The cathode of each diode is also coupled through a capacitor 66 to input signal bus 68. Each combination of resistor 60 and capacitor 66 comprises a dilferentiating network. A source '70 of input pulses or waves 76 is coupled to bus 68. Preferably, the waves 76 have a sharp leading edge; their time duration is not critical. The waves 76 are differentiated by each resistor 60-capacitor 66 to provide a sharp pulse at the cathode of each diode 62.

In operation of the circuit of the invention, and with the set of potentials shown, with the various resistors properly selected, and with an electron beam flowing to the 1 position, the l spade is at about ground potential and the 1 target is at about 55 volts positive. All of the other spade electrodes are at about 55 volts positive, and all of the other target electrodes are at about 150 volts positive. With these potentials present, it can be seen that the diode 62A is slightly forward or slightly reverse biased. All of the other diodes 62 are rather sharply reverse biased. Thus, it can be seen that, when a counting pulse 76 of about 50 volts negative is coupled through bus 68 and the capacitors 66 to all of the spade electrodes, only the first diode 62A is properly biased to couple this pulse to the spade electrode 16 at the 2 position. When this pulse is applied to the 2 spade, the electron beam switches from the 1 position to the 2 position. When the electron beam flows into the 2 position, the potentials are altered so that the second diode 62B has the same potentials on its anode and cathode, and all of the other diodes are reverse biased. Thus, the next input counting pulse can be applied only through the second diode 62B to the spade electrode at the 3 position, which thus causes the electron beam to switch to the 3 position. In this way, each counting pulse causes the electron beam to be switched from one position to the next.

From the foregoing description, it can be seen that the invention provides a relatively simple single-ended drive circuit for a beam switching tube, with the driving operation being performed by relatively non-critical nonquantized pulses.

What is claimed is:

l. A counter circuit including an electron beam switching tube having a cathode and a plurality of groups of electrodes; each group comprising a tube position to which an electron beam can flow from said cathode and including a target electrode which receives an electron beam and produces an output signal therefrom, and a spade electrode which holds an electron beam on its associated target electrode, and also serves to switch an electron beam from one group of electrodes to the next;

said cathode being connected to a reference potential;

first means coupling said spade and target electrodes to operating potentials;

second means coupling each target electrode to the next leading spade electrode; and

an input signal line coupled to each of said second means between each target and the next leading spade electrode;

the operating potentials and said second means being such that when an electron beam flows to a tube position, only the next leading spade electrode which is coupled thereto is able to receive an input signal from said input signal line.

2. The circuit defined in claim 1 wherein said second coupling means includes a differentiating circuit.

3. The circuit defined in claim 1 wherein said second coupling means includes a resistor and capacitor, connected as a differentiating circuit, and a diode connected between said resistor and the adjacent leading spade electrode.

4. The circuit defined in claim 1 wherein said second coupling means includes a resistor and capacitor, connected as a differentiating circuit, and a diode connected between said resistor and the adjacent leading spade electrode, said capacitor also being coupled to said signal input line.

5. The circuit defined in claim 1 and including a source of signal pulses coupled to said signal input line, said signal pulses comprising step Waves having a sharp leading edge.

References Cited in the file of this patent UNITED STATES PATENTS 2,797,357 Kuchinsky et al. June 25, 1957 

1. A COUNTER CIRCUIT INCLUDING AN ELECTRON BEAM SWITCHING TUBE HAVING A CATHODE AND A PLURALITY OF GROUPS OF ELECTRODES; EACH GROUP COMPRISING A TUBE POSITION TO WHICH AN ELECTRON BEAM CAN FLOW FROM SAID CATHODE AND INCLUDING A TARGET ELECTRODE WHICH RECEIVES AN ELECTRON BEAM AND PRODUCES AN OUTPUT SIGNAL THEREFORM, AND A SPADE ELECTRODE WHICH HOLDS AN ELECTRON BEAM ON ITS ASSOCCIATED TARGET ELECTRODE, AND ALSO SERVES TO SWITCH AN ELECTRON BEAM FROM ONE GROUP OF ELECTRODES TO THE NEXT, SAID CATHODE BEING CONNECTED TO A REFERENCE POTENTIAL; FIRST MEANS COUPLING SAID SPADE AND TARGET ELECTRODES TO OPERATING POTENTIALS; SECOND MEANS COUPLING EACH TARGET ELECTRODE TO THE NEXT LEADING SPADE ELECTRODE; AND AN INPUT SIGNAL LINE COUPLED TO EACH OF SAID SECOND MEANS BETWEEN EACH TARGET AND THE NEXT LEADING SPADE ELECTRODE; THE OPERATING POTENTIALS AND SAID SECOND MEANS BEING SUCH THAT WHEN AN ELECTRON BEAM FLOWS TO A TUBE POSITION, ONLY THE NEXT LEADING SPADE ELECTRODE WHICH IS COUPLED THERETO IS ABLE TO RECEIVE AN INPUT SIGNAL FROM SAID INPUT SIGNAL LINE. 